There have been known lamp units which employ a light source unit in which a plurality of semiconductor light emitting elements such as LEDs are disposed into an array (see JP-A-2008-10228, for instance). In the lamp units, a plurality of light distribution patterns can be formed by controlling individually the semiconductor light emitting elements to be turned on and off.
The lamp units described above tend to increase the production costs due to using a number of semiconductor light emitting elements.